A while back, I bought two guns - Colt Mustang and a S&W Model 10 - that were in similar condition. Actually, the Model 10 might not have been cleaned for 30 years. I started with the Mustang because it was bad, but not as bad as the Smith.
I field stripped it, removed the grips, put it in a small tupperware container, and poured in enough M-Pro 7 to submerge it. I let it soak for about a week. I took it out, brushed it everywhere with a nylon stripping brush (like a toothbrush but with black bristles that are much stiffer than a toothbrush - you can get them at the hardware store). When everything was loose, I sprayed it down with brake cleaner, let it dry and lubed it. It came out as clean a whistle.
However, if you want an easier way to get it really clean, take LogInName's advice and find an ultrasonic cleaner.
To clean the Smith 10, I have access (at work) to an ultrasonic solvent degreaser. I brought the revolver in on a Saturday morning just before they were going to change the solvent. I removed the grips, cylinder, and side plate and put the parts (sans grips) into a basket. This cleaner has 3 "bays" in it. The first is a vapor stage where the parts are placed into hot solvent vapors. I put in in there for a couple of minutes. The second stage is a vat of hot solvent with an ultrasonic transducer. I submerged it in that for about a minute, then dunked it in the final station which is a "rinse" in cold solvent. In less than 5 minutes, I had the cleanest gun I've ever seen.