I have two super sweet melomels going right now, a cherry and a pear/peach, and they're both really cloudy. I just tasted the cherry during racking, and oh god is it sweet. This is not a problem at all, but I have this irrational fear that clearing it will kill the flavor. My first batch is less sweet and tastes like mouthwash at the moment. It probably needs more time, lots more. Anyway, should I let the cherry sit for a while more in hopes that it clears? (It's tasty right now but cloudy, I'm really tempted to just bottle it.) Or should I try bentonite? (This is assuming that it's done fermenting... I'll know this for sure in about a week)
Also, apologies for how scattered and fragmented this is, I'm distracted and somewhat out of it from this storm, and the associated power outages.
Ok, so irrespective of whether you use any finings or not, a batch will usually clear over time, but there's often no real way of predicting how long it'll take. Yes, you can "cold crash" a batch if it's finished fermenting, but without gravity (or other test of remaining sugar content) measurements you won't know if it's finished, or a stuck ferment.
Very sweet, often indicates that you used too much honey in the batch and the yeast has "pooped out" at it's alcohol tolerance, or that the ferment is stuck (there's a number of reasons for that).
So I'd suggest that you try taking some readings to know exactly where the ferment has got too.
Also if you post the whole recipe that you've used and the method/technique then it's much easier to offer advice/suggestions/ideas about where to go next.
As for losing flavour when clearing ? No, the only flavour you'd lose is that of the yeast etc. Bentonite or sparkolloid, are both, I understand, quite "gentle" finings. Personally I've never had any issue with using the 2 part/24 hour finings, from the point of view of taste/flavour. The batch you mention that tastes like mouthwash, well I'd guess that is the "alcohol hot" flavour. Ken Schramm uses the analogy of "Listerine" in his book, I just tend to say that it tastes "medicinal". Either way, it normally mellows with time (it could also be fusels, but without the recipe/method/technique etc, it's hard to tell).
Apart from working out whether the very sweet batch is still fermenting, or whether it's stuck or not, it sounds like you're good to go.
Oh and cold crash would be to chill it close to freezing for a period (3 or 4 days ??) then racking it off the sediment.