I have heard of people in the old day mixing in paraffin oil, but I personally have just used straight paraffin with good results. All the original testing done by Friction Facts only used solid food quality paraffin. I suggest cleaning your chains again (i.e. strip off all oil) and using only straight food quality paraffin.
I gave hot waxing a try after seeing how well straight paraffin performed in a series of controlled tests performed by VeloNews and Friction Facts (2013 and 2014; both results are in the linked document).
Those tests used food-grade paraffin (i.e. must be > 99.5 percent pure to be labeled “Food Grade”). I watched Oz Cycle's video and some reason he had been using paraffin from candles, which could have less pure paraffin and other additives (e.g. perfume) that are not ideal for chain performance. So the first potential issues could be that you are using sub-par paraffin. Second, Oz Cycle also claimed, without evidence, that since straight paraffin wax easily flakes away from a candle with his finger nail, it will flake away from your chain leaving metal on metal contact, and hence need for paraffin oil to soften the wax. I find this claim dubious at best.
Let's look at the evidence. Friction Facts was probably the best source for detailed friction testing available to the public, before being bought out by CeramicSpeed. They had meticulous protocols and very accurate machinery, and didn't have any vested interest in the results outcome. They were hired by VeloNews to find the best lubricant available, straight paraffin won hands down. If straight paraffin simply flaked away from inner areas of the chain (e.g. the inner side of the roller) then the original Friction Facts testing would have immediately showed this problem as the 2013 testing also included extensive longevity testing.
From the original 2013 Velonews article:
We tested eight of the lubes for longevity, simulating a single dirty, wet ride and testing efficiency before and after.[...]
Once again, the old technology of paraffin wax vanquished all comers. In the longevity test, it was completely unperturbed by water, sand, and dirt; in fact, it was over 0.5 watts faster after being run for an hour in the grime. We believe that the wax needs to bed in a bit for maximum efficiency. And, since nothing really sticks to it, the goop was simply shed before it could slow anything down. The only other lube to increase efficiency after the dousing and dirtying was Park Tool’s CL-1.
The fastest bike lube isn’t designed for your bike at all. In every measure, the most efficient chain lubricant is simple paraffin wax, sold in solid blocks at any hardware store.
After you hot wax a chain, excess paraffin may flake off the outer surfaces, but this doesn't mean it is flaking off on the inside of the chain where 1) space is very restricted and 2) where you need the lubrication to be. If paraffin wax was flaking off from the inside of the chain, I don't think Friction Facts would have seen the stellar test. Given they were an independent testing body at the time, hired by VeloNews to get answers, I believe their results are credible.
The reason the straight paraffin wax likely does not flake away from the interior are for the following two reasons:
- Getting the chain very clean (i.e., bare metal, with no residue) before waxing means the paraffin adheres strongly to the internal surfaces of the chain; and
- The restricted space between the rollers and bushings means that wax that does penetrate into that area stays there as it has no where to go, especially in the hardened form!
As such, I suggest you stop using paraffin oil. Re-strip your chains back to bare metal, and get some fresh food grade paraffin wax. Leave the candles for romantic dinners with your bike.
A cheap and easy cleaning protocol I have worked out for dusty/dirty chains, as an alternative to an ultrasonic cleaner, is dumping the chain in boiling water and agitating roughly with a stir stick. The temperature liquefies the paraffin and the agitation dislodges the old paraffin and dirt. I then let the chain dry over night, before waxing the following day. I usually do 2-3 chains in one go. This is a "poor man's" ultrasonic cleaner, without the ultrasound cleaner apparatus nor ultrasonic compatible cleaners.