Remember, too, that finings have a charge as do many of the particles that are causing the haze.
All tend to change the flavor of the wine, although some only slightly, so you shouldn't use them unless you've already given the mead time and cold stabilization first to clear it without finings.
If after 4-5 months, and if the temperature has been dropped at least 10 degrees (that often precipitates the clearing), and the mead is ready to bottle except for clarity, you could try finings.
For a haze caused by yeast, which is negatively charged, a positively charged fining like sparkelloid would work great. For a haze caused by proteins, you'd need a negatively charged fining agent. For a haze caused by fruit pectins, pectic enzyme would be the best thing to use. Bentonite works great on proteins, but not on negatively charged particles, so it may not work well if the cause isn't suspended proteins.
So, for the haze you have, what do you suspect could be the culprit? Knowing that, or at least guessing at it, may give you the best shot of clearing it.