Please could someone suggest a way to stop or slow down the rate at which the sealant left in (say) a tube of bathroom sealant goes off / solid? I bought a whole tube, but then only used a little bit. A month later it's solid and so I've got to buy another one! I've tried putting some cling film over the opening and screwing the nozzle back on but that doesn't seem to help much.
Any ideas would be much appreciated.