I asked my pharmacist to see if they could order in some IDA (industrial denatured alcohol) back along – (ie meths without the methelated / emetic compounds which make ‘meths’ undrinkable). They could … but it was ~£35.00 ex-VAT for 500ml a ltr so I stick with meths in my trangia any carry my fuel outside my bag – (I only wanted IDA as any spillage in my bag wouldn’t stink everything out).
I did get them to order me some isopropyl in tho’, as I use it as an electrical contact cleaner, or when trying to get outfitting to stick to a rotomoulded PE hull – It was [only] about £4.50 for 500ml.
I don’t think I’ve ever cleaned my rotors in a structured way, certainly not with any kinda degreaser – at most they get the odd rinse through from the water my bidon at the end of a ride.