I've used Oatey 15806 Hercules Megaloc multipurpose thread sealant in the past and have had good luck. This time on brass fittings - the sealant wouldn't stick to the threads - not sure if the new fittings have an oil film or not but was a bit disappointed with the application - we only apply sealant to the male threads and I've mixed the sealant several times , hoping it would stick better or at least get between the threads, but ended up switching to a different product. The only thing I remember from the past is that "Megalok" easily wipes excess from fittings - unlike other products, the product has not changed in this regard.