Absolutely you can. And is recommend to do this 3-4 times up to harvest (about 10-14 days before chop). She will technically be drowned for a short period of time, but that happens when we feed too. Your medium can only take up so much water, so flushing excess amounts of water will just run through and won't be retained much more then if it were doing a normal feeding with run-off.
There's a decent way to expedite this process with certain soil flushing agents that are able to pull in excess salts faster. You apply with run-off, wait a bit and re-flush with just water about 30-60min later. By then the agent will have had ample time to grab additional salts and are disposed of with the second flush through. I was able to completely drop my excess salts with 3 uses in 10 days with this. (Type was "Flawless Finish" by Advanced Nutrients.
If you choose to just use water that's totally fine, it just may take an additional flush and a few more days.
Hope this helped my friend. Give me shout through PM if there's anything else I might be able to help you with.
Cheers and happy trails 😉👍