My question is why does this guy think the canister CAN be cleaned? Is the canister causing some problems?
The charcoal inside it is what picks up the fuel vapors. The canister will last a long time, if the fuel is allowed to purge. But just like when using charcoal to filter the water in your fish tank, the charcoal does lose its ability to absorb.
Pumping fresh/clean air through the canister is the only way that may work. Air from your compressor will have too much oil to do any good.
Go back and tell the guy that after an exhaustive search, you found out you need synthetic Charcoal Deactivator to clean the cannister, and for him to find you some.
It should be shelved next to the cleaner for the inside of the mufflers.
Come on guys, he can't even get to it w/o a left handed wrench and pipe stretcher. The 83 Corvette uses the same canister- have 'em look it up under that.