I doubt you can sharpen anything on jeans, stroking or not....I have heard that you can sharpen dull DE razor blades stroking them several times against a pair of old denim jeans?...
Don't need to test. One can polish an edge with a buffing wheel. Using a buffing/honing compound will make that edge perfect....Is this effective, have someone tested it and can say me if it helped?
I agree, do not sharpening but align the blade. I use this approach on 3+ blade usageYou're not really sharpening, more like stropping the blade. You might improve the shave qualities a little bit by smoothing out some rough edges. Most of my blades cost 10 or 15 cents each, so to me it makes sense to just replace the tired blade with a fresh one.