Interesting.
I just had beef tongue a few weeks ago, but boiled it as I've done in the past. I would think it would be necessary to boil it first and remove the covering in order to receive the benefit of smoking.
I won't have another tongue until December when my next half beef is ready so I...
I used normal masking tape, but did use a center punch to keep the bit on track. Lower speed, not too much pressure and the result was good. I also used a bit of oil, don't know if that really helped, but it made me feel better.