The common steel canisters seem to weight 30g, full (including carton packaging), with 8g payload. The vacuum ISP of a N2O monopropellant is given on Wikipedia

The common steel canisters seem to weight 30g, full (including carton packaging), with 8g payload. The vacuum ISP of a N2O monopropellant is given on Wikipedia as up to 180s, but the cartridge weight drops that to 48s. One could be chilled with dry ice to a vapor pressure of 2bar, but it's still far from easy to handle when weight is a substantial issue and you want to dynamically control flow, I'd figure.