One of the pre war motorcycle gearbox manufacturers (Albion, Burman or Sturmey-Archer) recommended boiling contaminated friction material in petrol to clean it! Not even I would attempt that!
Arwyn
When interest rates were 14% and incomes rather lower I ran a Series III Landie with major swivel hub incontinence issues. Whilst raising the cash for new swivels, 1 replacement hub (old one butchered by previous owner) and new seals, I would remove the brake shoes, scrape the worst of the oil off, place them on the concrete patio well away from house and garage, douse them in petrol and throw a match at them. Not something I would try today but it kept me mobile.