Stall is quite viable in UU I have found since I have started fiddling around in the tier. One of the biggest threats to any stall team is clerics (and magic bounce). I would like to discuss good checks and counters to the clerics in this tier.
A few things to consider:
1. Most threats to stall in UU are weak to Fighting (Blissy, Umbreon, Mega Absol, Steel types).
2. Florges is weak to Poison and Steel.
3. Hitting physically is much better than hitting specially.
4. Knock Off and Pursuit are handy tools to have.
One answer I came up with is Toxicroak. Both of his STABs hit all of the above threats super effectively plus he gets Knock Off AND Pursuit. Poison Touch also helps wallbreak and deters Wish to an extent because they will want to Heal Bell off the poison. Dry Skin I'm sure could potentially help in some way as it is his best ability, but none of the above threats use water attacks so I feel that extra boost to his damage and synergy with stall is better.
Something along the lines of...
Toxicroak @ Life Orb
Ability: Poison Touch
252 Atk/252 Spe/4 HP
Adamant Nature
Poison Jab
Drain Punch
Knock Off
Pursuit
Any other ideas?