Empty gro bags like this. More like plastic raised beds I suppose Those look like a good idea! I've seen 1 tonne builders bags recommended, and those are a sort of cut down version.
Monty washes his pots, so I do. I actually did mine when I did my autumn tidy up. I've never washed mine, but I did last year. I've got a 30 years accumulation of pots - it took me a long time. The trouble is all the pots that have come vacant since then. I can't be bothered to be doing repeated washes all through the year.
If you can't face doing them all, it's more important to do seed trays and small pots - larger plants are more robust. And of course any pots with sign of disease for example root mealy bug. If you're not going to wash, then at least let the pots stay dry for a few weeks before using again - I work on the principle that anything flourishing in moist soil may find it a struggle to cope with prolonged drought.
Peas are lovely , but I would caution as you only have the 3 bags . You need to grow masses to get a decent pick of pods , Mange tout, or even better, sugar snap (which you pick at a greater state of maturity) give a decent crop when you have only a few plants.
@Lovemusic33 Not planted in trugs like yours, mine usually eventually split down the side when in use as a carrier for compost. They should work fine, but I would recommend filling in situ and not moving around too much.