Welcome to ECF faisal!
Congrats on getting a nice setup!
I have an ebarron dripper. I used it with cotton rather than silica so you should be all set to use the muji cotton.
You need to clean the connections regularly. Taking care of the ProVari is easy. You just need a Q-tip and 99% (or 91% isopropyl alcohol). Here are some old videos that may help you, sometimes it's easier to watch than explain:
To keep the threads turning smoothly, try to find Noalox, it works well.
First, if they're dirty, clean the threads on your ProVari with a napkin, paper towel or microfiber cloth. If they're really dirty you may want to use a brush to clean them out. Then apply a small dab of Noalox on the threads and screw the cap on and off a couple of times to spread it evenly. You don't need much, a little bit of Noalox goes a long way. This video may help you too:
Enjoy!