how do i flush between veg-flowering?

fox farm schedule says the last week of veg to add in 2 drops of bushdoctor with your veg nutes...should i do that? or i feed twice a week every week so on the 2nd feed of the last week of veg can i just do bushdoctor no veg nutes? what are your opinions guys? thanks for the advice

for the record i use fox farm growbig/bigbloom in veg
for flower i use tiger bloom/big bloom as well as the 3 part solubles


PLEASE HELP!