ie/some have said alkalisation can be damaging for type As (me) or that only if it is heavily alkalised.
If they are forming mineral hydroxides (OH) molecules then it can be damaging regardless of your blood type. Hydroxides are some of the most powerful free radicals known, and they chemically burn the tissues.
If you want to alkalinize you are better off with deep breathing and eating more fruits and vegetables or nutrient rich herbs like nettle leaf, alfalfa or seaweeds.