Myth you need to wash the tank as often as you can;
Truth you should actually wash as rarely as possible, because the longer you leave the system by itself, the better the system works. You should have good filters attached to it and ensure that the water is oxygenated well.
Myth you should replace all the water from the tank and replace it fully with new water every time you wash the tank;
Truth you should actually replace only 20-25% of the water, otherwise you will create an imbalance in the system and harm your fish.
Both of these are incorrect. I know lots of folks that do 50% to 90% changes daily along with wiping down the tank...........beneficial bacteria is in the filter media not in the water or on the tank. Now if you get PH spikes because of your tap water not being stable, then it's a different story.