I have always maintained that solubility is very important to fish. Some swear by that 'washed out look' whereby a boilie/pellets has been left undisturbed for ages giving fish the confidence to eat it? I think it has more to do with solubility than how long it's been sitting there uneaten, otherwise if it had leached it's flavours more efficiently, it would have already been eaten imo.
Many years ago a friend of ours once challenged us to a friendly saying he was catching well on his secret bait up at a local canal venue. At the time he didn't reveal what he was using for bait but we each wagered £5 and took up the challenge.
I remember we used a variety of baits including bread punch, caster and expanders - each of us beating him by a couple of pounds. It turned out our mate was using jelly babies which were unnaturally flavoured and far less soluble. Now had we not been there? In the absence of bait choice for fish to choose from, he may well have had a better day on jelly babies!