For the once a year deep clean I have used a tape called "Metalace"
It is an impregnated tape about 15mm wide and is meant for cleaning spokes,tubes pipes etc.
I get this from Cromwell tools but I am sure others like eBay &Amozon can do this
The packaging has a web address www.enginewise.co.uk

I don't have any connections with this company, its just a good product

Steve

Steve

Roadster 3.7, "Mustang Sally"