bleaching bleach ruined top

[MousyMouse]

cotton shirt
of course my favourite.
got a bit of bleach on the sleeve...
can I bleach the whole thing? or is it only suitable for gardening doomed?
how much bleach? in a bucket over night?

I've tie-dyed favourites after similar accidents, usually just tieing pinches with string and moving it round in a bucket, maybe a quarter-mug of bleach in lukewarm water until it's a good colour, never left it overnight, more an hour or so as I remember.
An alternative is using white embroidery thread (silk) and white fabric dye to make a simple pattern round the bleached bit, then adding more of similar design on both sleeves, if you like relaxing sewing jobs. (Had similar accidents before).

thanks