"what should we expect to remove by boiling with dish washing detergent?
Be careful here. There is a remarkable difference between dish washing
detergent and dishwasher
detergent. The former is mild enough to soak your hands in while doing the dishes. Dishwasher
detergent is designed to work inside a dishwasher. It is much stronger
Lye, drain cleaners, dishwasher detergent and the like are used to clean dirt and organic materials from the surface of traps. They will not remove rust, paint, or "dips" either water or petroleum based.
The acids you mentioned, dilute hydrochloric (muratic) and dilute acetic (vinegar), can be used to actually clean rust off of traps. Muratic is fast acting but must be neutralized
after you use it. This means boiling the trap in a base solution. This could be any of the cleaning compounds mentioned above. You could also use a heavy solution of baking soda in boiling water to neutralize acid soaked traps. Frankly, I think the average person would be better off using the vinegar soak even if it does take a few days.
Dips are another matter entirely. You can remove most petroleum based dips by soaking the traps is gasoline, then use a paint brush to lightly brush over the trap, this will wash away most of the dip. Another option for removing dips, and possibly the only option for removing water based dips, is to tumble the traps in a cement mixer loaded with sand and/or gravel. (I hope someone else will comment on this as I haven't used that method personally.)