If it were me and I had the Lanocote already, which I have, I would use it and not bother spending money
on any of the alternatives. I suspect Tef-Gel, which is also a well regarded product, is only appropriate for use as a thread/rivet etc anti-seize compound though and not for filling exposed voids in fittings to prevent collection of water
or dirt - that is something I would double check on before using it in that way anyway.
If you are intending filling voids I don't think you will really have problems with Lanocote washing
out - the builder
of our boat used it on the rigging
screws (they are a special barrel type which are susceptible to problems if dirt gets inside them) and the deck
is stepped in it - all just heat gunned in and left to set.
I have after 13 years only recently given the rigging screws a touch up to refill the shallow recess around the top of the barrel threads just in case. The threads and interiors were still properly coated, as were the locking screws, but there was some erosion of the Lanocote on the shallow top recess in the barrels due, I expect, to rain running down the wire directly onto it. The lot around the mast
in the deck
step looks the same as the day the boat was launched.
As for screws and bolts, the genoa furler
ss ones were done with it also and when I disassembled the drum and part of the foil a year ago to fit a new top halyard
swivel they were all still properly coated and free despite the fact that the drum is exposed to seas and the components aluminium.
I have not heard of any problems from others were Lanocote has been appropriately used and that despite its wide usage. But in the end it is obviously a personal choice what one uses -there are a number of alternative products out there to choose between and worth looking at if one is so inclined.