most agastache grows so well from seed that i wouldn't bother with cuttings. i did root a few broken stems though...very simple, mist a few times a day, fast draining soiless mix...and i don't even think i used any rooting hormone.

Both will root well from cuttings, with or without rooting hormones. I just stick them in moist potting soil and set them out of the way in bright shade. If your air isn't humid you might want to cover with plastic to increase the humidity. Malvaviscus (turks cap) will often have seedlings popping up around the mama plant. These are easier to dig and pot up then waiting for cuttings to root.

I know the agastache grows easily from seeds.

I don't think it is possible to kill a Turk's Cap. I have dug cuttings off the burn pile that have been laying there for days and stuck them. They all rooted.

Good luck!

Janie