Google is not familiar with MS series pipe threads, so neither am I.
AsSumInG it is some form of tapered pipe thread, my preference is thick teflon tape for convenience and lack of mess. However, If there are components down stream that could be affected when shards and threads of teflon come adrift, some form of sealant is likely going to be "better."
Applying tape with an unusually high level of craftsmanship can reduce the risk of tape shred to near zero.