I am not aware of any means to actually achieve this without a real gravity well or accelerating to obscenely high speeds.

You could try to achieve a similar effect by subtly accelerating the clocks for the players but you are unlikely to be able to get much of a difference without people noticing what's happening. I think you'd get away with running clocks 10% faster, maybe a little more but any more than that and it would start to get obvious and take people out of the experience.

Most of the shows I've seen do this use some sort of direct brain interface to basically write an experience to peoples brains rather than actually speed time up for them so the character doesn't age in real life. Right now, we don't have any means to write memory directly or to provide more than very basic direct brain inputs or control so that's also a no