Most use them. You do not have to but the k-meta and sorbates help keep the bad things out of your wine and help to stabalize it so it does not referment.
Sulfites are generally used in the beginning to kill off wild yeasts and in the end game for longer life. If you have enough patience you probable wouldn't need the clearing agents. Does the recipe call for peptic enzymes to break down the cellular structure of the pears? If not, this could become an issue in clearing.
Brad
Homer definitely add pectic enzymes to your pear. Pear can be thick with pulp. I add 21 drops per 6 gallon bucket.
I would definitely use a clearing agent such as Sparkolloid or Bentonite to aide in the clearing. You will want to use k-meta (sulfite) if you intend on adding sorbate.
Carefully measure your sulfites and sorbate. Being off can result in problems.
Peptic enzymes were added per recipe, now we have a whitish layer (some might say scum) on top, I don't like to use the M word in mixed company but that's what it looks like, maybe it's like aged cheese? bk