Nope, I dont use it either. POR-15 and Eastwood both make nice engine paint kits. The basics of them are a clean surface. Many cleaners leave a residue, so they provide cleaners that address that problem. Both of those kits allow for being applied with a small brush, which is included in the kit.
I have tanked motors after painting them with the POR product and it stayed right on there. Also, I believe that both products cure better once the block is heated up.