There are two thoughts on this subject.
First, if you dump excessive amounts of fuel through the converter, it will glow verrrry red. This in itself would probably result in some kind of " cleaning " action.
Second, again as I stated a while ago, Ford had a recall on my 1988 5.0 Mustang, to replace all 4 catalytic converters because of oil contamination.
When they tried " low tension " piston rings ( to reduce friction ), it resulted in excessive oil consumption, hence destoying the converters.
