I hope I'm proved wrong, but I'm taking a guess there's hardly anyone one here who knows the town - and its pubs - well enough.
Can I suggest you do an online search for 'Haslemere pubs' and look for sites like Beer in the evening, Tripadvisor, Yell, and others, which include user reviews. These might give you an idea if an establishment is worth considering or best avoided, while you can also find their phone numbers or email addresses.
I'm sure some of them would be glad to have the custom of ten walkers - providing they leave their muddy footwear outside!
As a one-time leader of natural history and botany walks myself, I used to research the day extensively, the best part of which was checking the pubs