+1 to the emulsion side out technique. You could also make your own small tank, my 16mm 100' tank design is 2 pvc pipes, with a 1cm diameter difference between the outer diameter of the inside pipe, and inner diameter of the outside pipe, you could make a small version of something like that.
In case you cant find a suitable reel:
A 10cm diamter inner pipe, thats 7.2cm tall for the developing area, would fit a normal ~111mm length of 110 film, wrapped in gaffer tape with a 2mm wide spiral guide cut out (approx 4 revolutions) to stop any slip.
With a outer pipe of approx 11cm inner diameter, that'd take 120ml of developing solution.