I assume this is the extraction you are refering to
Yes, I can help, but first let me tell you a better way to do this:
Freeze precipiate your spice in a 1/2 pint mason jar with the lid on. When it is time to get your xtals out, carefully decant the liquid into another mason jar. Use a spoon to block off any stray xtals that might be floating around. When you are done, turn the mason jar upside down (the xtals should stick rather well to the sides) and get those last drips of naphtha out...even a small puddle can dissolve a lot of your spice when it warms up (and it can warm up quick!). Scape out with a spatula, knife, or spoon onto a plate and let dry.
Now, for your issue. What kind of filter paper are you using? A papertowl is going to be harder than science filter paper. IF you are using a papertowel as your filter. I suggest getting 20-40mL of HOT naphtha and soaking the portion of towel that has the spice on it. You want it to completely dissolve. Save that 30-50mL of spice laden naphtha and put in a warm, dark place for a day or two. It will completely evaporate and you will have just done a recrystalization as well as recover your spice. If you let it completely evap slowly you will have grown large needle like crystals.
If you are using science type filter paper: let the crystals dry. once dry use a razor blade to gently scrape off as much crystal as you can. To recover the rest you can refer to the instructions about. If you do try to recover what is still in the cracks of the filter paper, I suggest using a VERY small amount of hot naphtha (or even better Heptane (aka Bestine), like 5-10mL tops.
I don't use filter paper for spice extractions. I lose too much doing it that way. Decanting from a mason jar has been the easiest way I have found that will always work. If you accadently loose some crystals from teh original jar, they just end up in the naphtha collection jar and can be decanted again. 1 thing to really keep in mind is that you don't have a lot of time to work with. You want that naphtha away from your crystals as quickly as possible (but don't rush so much you spill your work). Naphtha heats up quick and will start redissolving your spice as it does.