auuuuuhhhhhhhhggggggggg i'm getting pulled in too many directions, brake lean, acetone, gas (petrol), tsp, prep and etch, denatured alcohol, mineral spirits! this tsp stuff can i just rub it on with a rag, cause thats all i'm interested in, no 3 weeks wrestling the angle grinder with a wire brush or a sanding disk, i also don't own a pressure washer. all i care about is that it works good enough and requires minimal work!
Relax, Use what you got.

There are may different ways to accomplish the same results. Acetone first (with appropriate safety precautions), change out your paper towels often, or you will just be spreading the oil around. Then, follow the directions of the paint manufacturer. I see you bought primer and paint, just follow their recommendations. I assume you wire brushed your welds to remove any flux. After the Acetone, just wash everything with dish soap and water, but hose everything off before it has a chance to dry. Otherwise any residual oil is left on the metal.
If you want to see the effectiveness of dish soap, just add a few drops of oil to a wide shallow container of water. Then add a few drops of dish soap (dawn works best, but any dish soap will do) on the oil and watch what happens. (Old Boaters trick)
That's why I recommended the pressure washer with the TSP, you have to rinse off the cleaner, before it dries. I usually just hit it with a sanding disk on the grinder after that to get it nice and shiny.
With Acetone, just keep changing up the rags until you see no more oil on the rags. Follow up with the soap and water, just as a cheap precaution.
It really is simple in the long run, and once you have it all cleaned,WEAR GLOVES, do not touch the metal with your bare hands or you will leave an oil residue behind (fingerprints)
Take your time with the spray cans, you have no control over the width of the spray, or the amount of paint being dispersed, so many light coats will yield a better finish than trying to put down a couple of heavy coats.
