I've been using 70% isopropyl alcohol to clean rails, with satisfactory results. I've also read that some use denatured alcohol instead. For those who use - or have used - either one or both of these products, what's been your experience? Has one or the other proven to be more effective keeping your tracks clean and your locos running smoothly? Or, does it matter? Even though denatured costs more, I'm interested only in each product's effectiveness, not cost benefits. Also, please no comments on other types of track cleaning materials; alcohol only for this thread. Thanks!