While restoring my M20, I could have used this clever DIY parts cleaner made from readily available garage tools and parts. However, I would use a bio-degradable cleaner such as Simple Green Cleaner, available at local hardware stores at modest cost. For corroded parts, I would use the same cleaner, adding a small amount of kitchen vinegar, and heat the mixture in the microwave before use. Heating diluted vinegar and soaking / agitation really accelerates the dissolution of metal oxidation and mineral scale. I use it periodically for deep cleaning of household faucet spout bubblers and shower spray heads. Some care is needed, as hot vinegar will remove paint.