Engine oils are generally a bad idea on a bike. They tend to be quite liquid and will dribble out over time. Engine oils are also known to grab and hold dirt, because that's one of their purposes in a motor where there is an active filter.
Your best lubricant for pawls is a lithium based grease, sometimes called white lithium. Avoid using too much. If you don't want to buy that, then grease is your second best option. Again, use just-enough but not too much which will gum up the works over time.
In a pinch you might mix some grease with a few drops of 3-in-1 to thin it down, however generally mixing lubes like this doesn't work well. Grease and some Oil mixed should make for a thinner grease (not a thicker oil).
Consider how hard it is to service inside a freehub/freewheel and whether you want to go through that effort any more often than necessary.
Any lubricant is better than none, so engine oil would rank above zero, and above water but below lithium or grease.