How long to flush?

[Skools Out]

i taste the water coming out the exhaust after couple mins and if it taste salty i check it again a couple more mins later then usually good so then i run it after no salt taste couple more mins. but the last 2 min after the salt taste is gone i rev the motor up and hold it around 3500 then pop it up a couple times to get the salt out of the high rpm water over flow lines. then shut her down.