I generally clip on the Park chain cleaner, fill it with a cheap department store degreaser (Rubbermaid), run it through for a few seconds, then fill the chain cleaner with water once or twice or more to get rid of the degreaser. I've been trying out Purple Extreme lube lately. I'm not getting 100 miles out of an application of Purple Extreme (Conditions have been wet, but not "extreme") . I'm convinced that some of the degreaser stays behind and breaks down the new lube. Could this product contain detergents that stay behind and destroy the new lube? Is this the difference between $10.00 per gallon department store degreaser and $50.00 per gallon "Bicycle" degreaser?
It's certainly possible that degreaser is staying around and breaking down the lube. I use a citrus degreaser (green label but I don't remember the name), and I've never had issues scrubbing it off the chain or cassettes. Also make sure you use a rag to wipe the chain down before you apply the lube.