Not that I've had great luck either, but when I have bought the stem plants, they come with flexible weights wrapped around the base of the bunch. I inquired and found that these weights do not contain any metal, so you could perhaps reshape and resposition them to just hold the plants down? I'll probably try that next time I buy a bunch. My most recent purchase, I just got the mini-potted ones.
The Boy Feesh: Indigo CT, Lavatail CT, Ghost CT, Chicory HM, Redfish VT, Magic DT
The Girl Feesh: Christmas CT, Shine VT, Snowflake CT, Stripes VT, Midnight CT, Grif VT, Tangerine VT, Wraith CT, Amethyst VT, Ice CT, Poe CT, Turquoise II CT