TJay, I'm about to widen my 3 and would like to copy what you have done rather than simply order the Murle kit. Could you post some additional pictures of it? Top weld, middle, front back and what tube size(s)? Pretty please?
When it comes to water based cleaners yes, most substitutions will work. but some evaporate differently then others, some may leave a residue that could act like a release agent on your topcoats. Read the product sheets carefully. I worked in the paint industry for twenty years as a painter, tech rep and factory sales rep, for Akzo, (Sikkens), Standox, PPG, Sherwin Williams and Poly Fiber. I'll just say this, gun cleaner is usually made from recycled solvents, it can have silicone, glycol, oil, water and other nasties in it that I would't want anywhere near any my paint work. There's a reason it's cheaper than a pure solvent. Same reason I wont use recycled rags on anything I'm painting. Your el-cheapo lacquer thinners, (the 5 gallon pail types) are also usually recycled and contains the same crap. Even after washing a gun out with the cheap crap, I'll still put a few ounces of $50+ a gallon thinner/reducer thru the gun just to clear the crap out. I left some el-cheapo gun cleaner type thinner in a cup of a not-so-cheap Devilbiss spray gun for about a month once and opened the cup to find the bottom of it all corroded. That can only happen to an aluminum cup from water! A blending solvent is usually the purest virgin solvent you can get.