Re: Cleaning Motor Chain
The easiest approach would be to drop the chain into a parts washer and then relubricate.
If that's not an option, you'll need to do this manually. As the chain oil will capture the grit, you'll need to remove both. Fill a bucket with your favorite degreaser, add the chain, and agitate to dislodge the oil and grit. You'll probably need to repeat this a few times to get all the grit off, as the degreaser becomes less effective as it gets loaded. If you used a solvent, air drying is probably sufficient, and don't forget to relubricate the chain when you're done.
For degreasers, I've had good luck with Simple Green (leaves a residue, but is water-based and reasonbly nontoxic), mineral spirits, and some of the stronger cirtus-based degreasers.