Tomato ring culture

Because P is replacing some of the floor in the shed I had to have a bit of a sort out to expose the floor. I found a packet of old but in good condition Fyba ring culture pots. Basically floppy pots with no bottoms.  I see they recommend using them with growbags.  The query is:  are they of any benefit placed on the gh border soil that is dug down to  say 2ft?  If so I'll experiment next season, if not they'll probably get shoved back into  the hidey hole they came from