[hisnhers]

Amazon.co.uk

Found it on Amazon. Although it’s out of stock 🙄

found this one on ebay

Worn Piston Rings Blue Smoke Treatment For Classic Car Engine Burning Oil Fix | eBay

Find many great new & used options and get the best deals for Worn Piston Rings Blue Smoke Treatment For Classic Car Engine Burning Oil Fix at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

I can't see this being a great solution to the problem. It's an oil additive that thickens the oil to reduce blow-by. Might provide a temporary fix but you'll probably destroy the multiair unit which is very sensitive to having the correct oil.
Takes me back to the days when sawdust was a recommended solution to a noisy gearbox...