aquarium pump engine drier
About 15 years ago, I parked my 182 because I found magnetic particles in the oil and didn't have the money for a tear down. After a year or so, I became concerned about corrosion and bought an aquarium pump at Mal-wart, ran the outlet thru a liter of laboratory drier (Drierite as I recall) that I had laying around, and from there thru a small particle filter into the oil filler. I didn't plug the intake, but rather left the pump inside the plastic I wrapped the engine in.
With one thing and another (new roof, kids' college, etc.) I wasn't able to do the teardown for ~8 years. When I did, the parts of the engine beneath the pistons (cam, crank, etc.) were as shiny as new (metal turned out to be from a failed starter adaptor, which is a whole 'nother story). The upper cylinders had a "very light" coating of surficial discoloration (prob rust) that the IA honed off before reassembly. Its been another 4-5 years and 2-300 hrs on the engine since then with no indications of any problems.
I checked the dessicant for moisture ever month or so, but only had to change it 2-3 times in that whole period.
I understand the argument about closed loop systems, and can't argue about the theoretical advantages, but mine wasn't and it seemed to work, based upon the indicator in the drierite, and the condition of the engine when we reassembled it. Granted, I live in a fairly dry climate (6-8" of precip), and the pump was in the same contained envelope as the engine, but I had pretty decent results with this very simple method. It certainly beats the old procedure of wrapping an engine with plastic and throwing a pillow of silica gel in with it.