I use TCP (which is a couple of years old) when I'm forced to buy 100LL. Works great as I've never had any problems with lead fouling.
The other idea is to run the engine at 1000-1100 rpm for a minute of so prior to shut down. For those with a mixture control you can lean it out as much as possible w/o stalling the engine. This is the recommendation in the Lycoming engine manual for the 0-235. You can also use UREM37BY plugs (if approved for your engine). I understand these were developed to help with the lead problem. Regards; Noel Anderson Canaan, CT
