I struggle with the similar stuff... it can suck.

I've found basic grounding (like naming things around you, trying to focus on textures or tastes, etc) does little to actually ground me. I had to be good at functioning while dissociated, so I learned to stay checked out through a whole host of stuff. It's not an inability to ground, or a resistance to it (well, ok, maybe a resistance to it, but only because that was useful to me at some point - I needed to act present even if I wasn't)...

I've found doing things that engage my brain helps me ground. Talking about things I'm passionately interested in, talking about my critters, trying to explain how to do something, etc, all help me ground. It kinda sucks, because I always need sometime else there who knows what's going on to get me through the process, but it's the only way I can do it.

As for your question about it not making a difference if you are home and safe, it only really makes a difference in your quality of life. Can you handle being dissociated? If so, and it doesn't make a negative impact on you or those around you, having to ground from it is in your control...

Dissociating is basically a safety measures some people use when faced with trauma (either prolonged, or very severe). It just got stuck in the "on" position for some of us. If you're not feeling safe, it tends to kick back in fairly easily...

my t doesn't focus on grounding as much as she does growing a sense of safety (unless it's the end of session and I need to ground to drive home). She has found that being able to feel safe helps the dissociation more than just simply trying very basic grounding. When I dissociate during session, we explore what's making me feel unsafe, and go back over all the ways I actually am safe in the moment. When I have to leave shortly, she has me talk to her about my pets...

I hope you can find a way to feel safe... do you have a t you are working with on this stuff? Would they be someone you can talk to about different grounding techniques when you need them?

(Sorry if this doesn't make too much sense. It's 3am and I'm not sure how much sense I can make right now)