A client, with couple of glass-houses, has been storing used 'grow-bags' (for garden beds' mulching etc), but I can have some and I'm not about to pass-up an offer of some very good fibrous compost material for £0 !
Accepting that soil-borne diseases will always be a potential issue, I should be most grateful to hear of successes and disasters with recycled grow-bags whether they've been emptied for bulk use or recharged with nutrients in the bag. To note; if I were to re-use in-bag, it would not be for another crop of tomatoes, chillies or similar.
[On offer are used deep-fill bags with seaweed extract from, I seem to recall, Thomson & Morgan.]