Not yet tried but it seems really hard to me, as I only have one Kyogre at level 33. I guess for me to win Claydol solo, I need at least power my only Kyogre to level 37 (its attack is 13), which requires too many RC that I currently don't have. Other than Kyogre, my only viable mon might be level 37 SC Gengar and level 40 SB M2. I won't waste my free pass on that as it won't reward me a mega relevant mon.
Claydol Solo Raid
Have you tried it yet? I did one this morning and it was, by far the most difficult tier 3 without weather boost (Gamepress was right about this one). So, I did a bit of analysis of the reasons why it's so tough:
- 3000 HP. That's one the main problems with Claydol. It takes a lot of time to take it out (Like any Tier 3 raid boss)
- So low attack and so high defense. According to Gamepress Claydol has 113.15 attack and 183.23 average. It hits so slow and so weak that it takes such a long time to charge your moves. It's defenses are higher than Donphan, Snorlax and Alolan Marowak raids!
I tried to beat him using 2 SC/SB Gengars and 4 B/Cr Tyranitars (All maxed out at level 40). I couldn't do it. Claydol endured with 5 ~ 10% of it's health left. So I tried again using only Kyogre. I managed to beat it only because I used the Lobby glitch, otherwise the clock would get down to zero.
Have you guys tried to soloing him?

Answers
Haven't tried, likely will not try unless there's no Mewtwo around to raid and this is the literal last raid of the day before curfew. With only one maxed SC/SB Gengar and one maxed Kyogre I don't trust myself to complete it unless the weather is on my side, whether that means fog, rain, or sun to bring in Venusaur and the Exegg bros.
Not true at all. Even against ES/EQ dodging perfectly, 1 Kyogre only takes out about 2/3rds of the hp before dying. Following up with a "random high CP" will result in a 100% chance of a loss.
(EDIT: without WB) You have Gengar and Kyogre that can get slightly ahead of the clock, Mewtwo that stays about even with the clock and about 5 viable fillers that lose time but not much. Funnily enough Mewtwo and Tyranitar are the only ones with a high CP, the rest of the top DPSers against Claydol have a pretty low CP.
I beat Claydol a few times on its original run without weatherboost with the following team:
L40 SC Gengar
L40 Kyogre
L40 SB Mewtwo
L40 Gyarados
L40 Tyranitar
It's stupid hard. The clock trick didn't exist back then so the run was heavily RNG and often took a few tries. I even failed it once after two successes.