The general consensus on sublingual DMT is that it is not a very decent Route of administration (ROA).

from this thread which I would recommend reading, it has a lot of great info:

DMT & Harmalas: Dosages and administration (oral, smoking dmt, sublingual, snorting, etc..)

And as another example, a highly respected member wrote:

So if the chewing tobacco is cutting up your gums, then maybe it would absorb better but it probably isn't worth it in the end, honestly. Just my .02