A $5 disposable e-cig and a $2 air pump (both off eBay) were used to in this smoke test.
I used a pair of cutters to remove the vented end cap. (“lit end”)
Heatshrink tubing was used to join the silicone tube to the tube.
Simply blowing into the tube causes the e-cig to emit smoke:
This is the same e-cig fed from a small DC air pump motor: