I got one on some new rock. I thought I was going to squash him when putting 2 pieces together, so I got a little aggressive. I pulled the rock out and literally peeled him off of it. Luckily he didn't expel anything. WHEW I wouldn't reccomend it, but it worked for me. I wouldn't do it again it wasn't very nice on my part.
IME form working with them in the caribbean cucumbers depending on the species are pretty tolerant to being handled. FWIW While collecting them for pearlfish research I never had a cucumber expel its innards
I got two last year. One expelled within hours of being placed in the tank. I did a quick water change (about 10%) after fishing out the expelled 'stuff'. No fish died and although I expect the cuke to die, he is still alive and eating a ton. I'll post a pic when I get home.