I say yes... Use three times the amout of water vs the size of your pot... Example, if you have a 1gal pot, use 3gal of PHed water to flush.... Also, as far your PH, in my experience kepping it as close to 6.5 is best. So between 6 and 6.5 is great... When and if you do flush, add a bit of H2O2 (available at any grow shop for cheap). Im not 100% sure but i think the stuff at the shops is around 30%. Directions are on the bottle but i think its 3ml per 1gal? Anyways, this will clean up any dead root matter and help oxgenate the roots. There is a down side to this though. It will kill beneficial bacteria but microbes can be bought and added later... So after flushing, wait untill the soil is dry a few inches down from the top or just simply lift the pot to see if its lite. If its heavy, dont water. If its lite, water with a weak nutrient solution. If you are using a bag mix soil, dont use any nutes for few waterings... One more thing to add would be watch how fast the water drains out... If its slow, your soil isnt draing properly and this issue will happen again. If it goes straight through, its not a terrible thing per say but you will have to water more often and you run the risk of the plant not getting all it can from the nutrient solution. If it comes out steady and somewhat evenly, your golden.