Julian, I can also echo your thoughts re: the use or non use of loctite as for those asking the questions "why are we even talking about this issue" in respect of the (op) he was merly asking the question should he use it or not and what purpose does it serve.... it had nothing to do with the cost of the drain plug and everything to do with the curiosity of having to use loctite or not and why..
If people don't know, they ask the question, however i still stand my point manually applied loctite or factory cured on the grub screw, unless you degrease the threads to which its being applied it renders the stuff useless.
Dave, for the sake of clarity ...
I agree the question was not literally about the cost of a new drain plug, but it was surely part of the bigger question i.e. about how to effectively fit a drain plug as part of the oil change process.
I have only ever seen advice about using Loctite in the context of fitting used drain plugs, taken together with the question relating to the "need to use Loctite when i replace the plug
", I made the assumption the opening post was about refitting the original/used drain plug (where application of Loctite is frequently advised).
On that basis, the option of fitting a new drain plug and the cost thereof has everything to do with answering the bigger question (as I interpreted it).
From this thread re-using drain plugs with or without Loctite is the solution of choice for many people (including Julian whose advice I hugely respect, and I also respect your advice about degreasing) but in this case my opinion is new drain plugs are a better solution.
In any case I believe that lateral thinking can be hugely beneficial, if we are to be constrained by the literal wording in the opening post then we would be much the poorer for it. In other words I would never discourage anybody from asking their question, but similarly I would never criticise anybody for approaching the problem from a different angle.
P.S. With hindsight I appreciate that the question may well have been about applying Loctite to a new drain plug, but I made assumptions based on having never heard of such an approach.