..u can use a test tube (of the right glass thickness, i.e thinner).

McKenna's glass pipe i saw was a custom blown job with approx.1 inch diamter bowl, and long narrow stem (say 15cm+, 5mm diamter).

this allowed all material to be vapourized before inhalation, the long stem preventing accidental aspiration of the liquid dmt (which 'burns'(sensation)  mouth & lungs).

lots of methods out there...