so using Drizzle and Swift Swim together are banned, but could you run something with Swift Swim on, say, an OU Sand Team, to help counter an opponents Drizzle Politoed on an OU Rain Team?
Yes, you actually can. Let's take a look at what Smogon says:
Using both a Pokemon with Drizzle and a Pokemon with Swift Swim on the same team is banned.
Your SS isn't on the same team as the opposing Politoed, right? So you can go and use (i guees you are using) Kingdra all you want, especially with the rise of rain teams.
Have fun.
