Pappy,
I don't know where you heard that Wipe-Out or Montana X-Treme damaged bores, but if you can put your hands on the reports I'd like to hear from you.
Many kinds of ammonia-based cleaners can damage bores, because they're water-based. This is why the instructions suggest running another patch through the bore every 15-20 minutes: The water has evaporated, and the solvent will pit the bore.
Both Wipe-Out and Montana X-Treme are oil-based, and the oil doesn't evaporate. Consequently you can leave them in the bore safely for as long as you want, and the bore won't pit. I have been using both for a long time, and my bore-scope shows no change in the bores of my barrels. They also don't foul any more (and usually less), and more fouling is a sign of very light pitting. (One exception may be the "accelerator" for Wipe-Out, which makes it work quicker. One independant test indicated it might pit bores.)
I had an electronic cleaner for a few years, and it was a PITA to use compared to Wipe-Out or Montana X-Treme.
