Just got done painting the rest of my interior parts SEM products. I gave them 4 different cleanings before adhesion promoter. GoJo, Dawn, Sem Soap, then 95%Isopropyl alcohol. The first 3 with a nylon brush and 3-M scuff pad. By the time I got to the alcohol, the rag didn’t even get dirty. I found a great little tool thats fantastic. It’s a refillable aerosol sprayer. Use either a tire pump or compressor to put air to it. It came in real handy for spraying the alcohol. I’m gonna buy a few more for WD-40 and Prep-sol