Well, in my game, players can use rope to restrain a lycanthrope, but they would be unpleasantly surprised if they thought they kill one with non-magical/non-silvered rope.
I guess lycanthropes in your game don't need to breathe to live? That's pretty cool.
So, you don't follow the RAW on lycanthropes? That's pretty cool too!
Sure I do. It says "Damage Immunities bludgeoning, piercing, and slashing damage from nonmagical weapons that aren't silvered."
Strangulation by rope doesn't fall into that category in my view so the damage immunity doesn't come into play. I think instead the rules for suffocation come into play. Lycanthropes aren't immune to that, according to the rules, anyway.
Rope is most certainly a weapon.
But, if you want to go with the suffocation rules, please refer to page 183 of the PHB: "A creature can hold its breath for a number of minutes equal to 1 + its Constitution modifier (minimum of thirty seconds). Given that a combat round is 6 seconds, good luck on keeping the lycanthrope restrained for the 20 rounds it will take to suffocate it. At the very least, a wererat could shift into rat form to get free of the rope.
I started a campaign in a small silver-mining town. In the town square was a big statue of a town hero holding a large silver pick. I introduced this setting and came back to it several times so the players would remember it.
You have to set it up ahead of time, though. Introduce the statue early and mention it a few times and make sure the players know about it, because sometimes they tend to zone out when you describe scenery.
Well, the game isn't called Anglo-Saxon Epic Literature & Dragons. The game has a set of rules and it cannot accommodate every type of literature out there.
And if strangling a creature is your idea of creativity, then you have a very low bar for imaginative problem solving.
How about drowning it in raw sewage?
So, you don't follow the RAW on lycanthropes? That's pretty cool too!