Yeah, at first I had some trouble because I had been soaking my caps and I asked them about this before ordering. They suggested their "recommended" procedure, which does take some time to do - The flipping them over and spraying the bottoms. At first I tried the soaking them, and they were actually just fine in the Iodine mixture we used originally...although at one point left a couple in for about (maybe) 10 minutes and it started to eat the sealing away. Although, again, the Iodine mixture itself said not to use more than 5 minutes, so this was my fault.
For the smaller quantities of caps I want at one time, it's a simple extra step for me to just go ahead and spray the bottoms. I couldn't purchase the 10K minimum that several other places advertised. And the caps turn out pretty cute. I haven't had any issues with the designs, they worked with me pretty well.
It's pretty much a matter of if you just don't want to take the extra time to ensure the design will be fine. Which is understandable, this entire procedure takes long enough as it is.
Hope that helps!