Purging lines

[CaptAwol]

I would like to try hop torpedo'ing with a hoprocket and fastferment conical, this will obviously require purging the lines with co2, as I don't use co2 I have nothing for this.
Being a co2 virgin can someone recommend or suggest what I should be looking at for this purpose of just purging

[Haydnexport]

a soda stream bottle and a suitable adapter perhaps?

[Fil]

with a bit of planning perhaps simply vent the fermentation co2 through the hop rocket to purge most of the o2, it will require unsealing of hops earlier, but once purged and ports plugged the whole assembly could be put in the freezer til primary has completed.

[CaptAwol]

with a bit of planning perhaps simply vent the fermentation co2 through the hop rocket to purge most of the o2, it will require unsealing of hops earlier, but once purged and ports plugged the whole assembly could be put in the freezer til primary has completed.

That's an option I've considered in the past, connect tube from airlock to a polypin bag and save the co2