My didgeridoo teacher had the class practice at home continuously blowing air through a straw - it still took me almost half a year to reliably be able to do circular breathing.

I have read a few references that humming or ‘ohming’ help sinus health and breathing so I guess it makes sense playing the didgeridoo would help also. Blowing bubbles through a straw won’t cause vibration, so probably in itself won’t help.