i have an almost identacle variety, only a little colour difference.
i completely cut the heads off them all the time. i do it in tank with sharp scissors, leaving about an inch of the stalk with the cap. i then sew it to the selected piece of rubble with nylon thread and place it in a low flow area while it heals. the stump left behind will grow a whole new head for me to frag again. they heal fast, with the sewed one sometimes completely opening up by the next day. the stump takes a couple of weeks to regenerate new tentacles. i do run carbon after a fragging session, and have never noticed any ill effects.
my clowns love them too.