Wow, I've never heard of that! As far as the squishing goes, I have no advice for you. I, however, have also had problems getting large crickets from my local pet store recently. What I ended up doing, though, is order some wax worms/meal worms online (since I've been unable to find them in local stores). These guys will keep fairly well in the small transport container with some oat bran (if you see that their food supply is dwindling). I keep them on hand for those "just in case" situations and they are also great to add a little variety to the frogs diet since they are more "treat-like" than nutritional staples.

I order from Josh's frogs online and have had good experience with that, but like I said, I use them as "just in case" treats when the stores are out of crickets so I've only had to order once.