Catalyst cleaner fuel additive

[Newbie57]

Anyone tried these? Any good?

[Essex2Visuvesi]

Cataclean works well... Used it in my RX8 every 6 months or so
Has been proven to be more than just snake oil on multiple occasions

run the car till the petrol light comes on. Add the bottle along with about a fivers worth of petrol and then take the car for a darn good thrashing. Fill up as normal and you're done
I always do my cars just before the MOT