I'm not familiar with Break Kleen.
Do you perhaps mean Break-Free CLP weapons cleaner or Brake-Kleen solvent for cleaning brake calipers?
I use both, Brake-Kleen when working on brakes and Break-Free for cleaning/lubing guns and tools. Break-Free works well on garden tools (cuts through sap).
Even though they'd probably dissolve tar and sap just fine I wouldn't use either on paint. Don't know how compatible they are with the finish (and Break-Free is primarily a lubricant, loaded with slimy oils). Even if they were paint safe neither will do zip for scratches and swirls, they have zero abrasives.
PC.
