Buy a wand like this.
Flush the pink and other stuff out of the WH tank.
I use less than two gallons when I do the lite I then dump the rest in the sink and shower P traps and some in the toilet bowl.
I think you should be fine.
A/F in the WH tank will not hurt anything but you really should not leave it in there.
2016 F350 6.7L LB CC Reese 28K 2014 Chaparral Lite 266sab
"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety." 2014 19 days camping 2015 17 days camping201620 days camping