You should seal the knots regardless of whether you bleach the knots or not.
Just spray some hair spray, or TDI, or 3M77 or whatever you use.
The knot sealer will prevent any excessive shedding.
You can choose to bleach or not to bleach. Until you feel comfortable
enough to do the bleaching, you may just want to do the faux bleaching
techniques mention in the forum. I, personally, do not bleach knots and
am still using the Sally Hansen tan spray technique posted by Sexi.