DuhAsianGuy
First Day On the Job
No, i dont use any HM slaves. Maybe once or so but i don't remember. If I need to use an HM I give it to one individual pokemon in my party.
I use them when I don't have a 6th member. It just makes training Pokemon easier and not worrying about using field moves on members that are part of your main team. I find HM Slaves very useful.