I guess the most forgiving soap I've got would probably Stirling Unscented with Beeswax...that stuff just tends to explode off the puck no matter what I throw at it. IIRC La Toja is pretty forgiving, too, though my La Toja stick tends to live in my Dopp kit and I mostly use it when traveling, so it's been a while since I've used it. Also, MWF is coming to mind...stuff isn't the easiest, but the key isn't dialing in the right hydration, it's just loading for ever and ever. If you load it long enough, the water ratio is really quite secondary. (Though also something I'm not using much anymore, since I seem to have developed a lanolin sensitivity.)