Fentanyl sublingual tablets

[Endoflifer]

Hi everyone, new here, but eager to get straight to the point, so I won't introduce myself otherwise than by saying that I live in the Netherlands and am able to get hold of Fentanyl sublingual tablets here, of up to 400 mcg. I figured I'd easily be able to hold 20 tablets under my tongue and against my gums and that combined with some benzo's, zolpidem and alcohol that should do the trick, 8 mg. But the more posts on the topic I read the more doubtful I become, also because sublingual tablets are hardly ever mentioned (even though I understand that their bioavailability is high and they are rapid-acting). Any thoughts on the subject?