While I am waiting for the handle for my DIY brush, is there any reason why I should not use the knot without a handle? Just hold it between my thumb and fingers, and go to town?
I did it once when a knot dropped out of a handle while soapy and wet. I was in a hurry and went ahead with the shave -- not too practical but it worked.
TBH I would wait for the handle to arrive, 1 the knot will be very floppy without the handle, 2 if you get a layer of soap scum on the base of the knot then you're going to struggle in gluing it in.
That's just my 2 cents worth but the choice is yours, Sir!!! If you go ahead please report back and let us all know how it went.