Generally, mine does not need to be blasted. I am just rinsing dust off. The tire foam even does a good job cleaning crap off of the fire wall. Plus it seems to protect everything from moisture. When I sold my 02 everyone that looked at it commented on how clean the engine bay was. Multiple people commented on the brake booster and asked if it was new because there was no rust on it at all and all the other 02's they looked at the booster was covered in rust.