Anyone using strong slow charge moves in PvP

Only use for Focus blast is on mewtwo, it and shadow ball are a beastly combo, bot focus blast on its own, not much.

Slow charging one in general arent good, getting off charge moves as fast as possible, which is why peiple use stuff like dragon claw and leafblade, shred oppoents shields and their HP fast, unlike the snow charge moves. They can be good if paired with a 3 bar, have the 3 bar for taking shields apart, then go in for big damage with the one bar charge move, or maybe just mind games. It takes a bit of the right senario, but on their own, one bars are bad, when paired right, they are fantastic

Yes - waste their shields with Dragon Claw or similar then decimate with Solar Beam. Works especially well with Latios.

I dont like them either.
Guess it is ok if you have 2 moves unlocked and one of them is a slow charge move.

Otherwise it's risky because of the shields.

My L35 Ivysaur has Solar Beam, and I don't think I usually get it off in the Great League because almost all of my opponents are finished before it even gets the chance to fire.

Very fond of Earthquake, it's a much better move in PvP than in Raids and Gym battles, and when paired with Mud Shot (not Mud Slap), which generates energy really fast (4.5/Turn, as fast as Thunder Shock and Psycho Cut) it's quite effective.

The other slow moves, not so much, especially Dazzling Gleam, which has to be considered slow in PvP.

It's how you charge the fast move that matters most of the time. Energy gain has more influence than the charge move itself, so a mud shot groudon can use earthquake just about fine but if you run dragon tail you cannot even run outrage properly.

The moves you mentioned are the 11th 12th and 13th best moves in the game respectively so I would tell you they're all extremely usable.
If you have a fast move that generates low energy gain any charge move is going to be terrible.
If you subtract Community Day moves and special moves the moves you mentioned are even better.
Doom desire, frenzy plant, hydro cannon, Blast Burn, meteor Mash, Draco meteor, origin pulse, and Precipice Blades
If you subtract those moves you're talking about the third fourth and fifth best moves in the game.
In short what I would tell you if you don't have one of the moves mentioned above those are hands down your best options depending on situation obviously.