Every remote control chastity toy that I've used with my subs are honestly crap. They die, break, split etc etc. I removed them all from my store since I don't feel comfortable selling them after they broke or didn't connect to my phone properly, or split.
If I am doing remote then I like to use numbered plastic padlocks and then I can see the number when its put on, write it down and you can't remove them without breaking them, so a quick inspection lets me know its not been tampered with. It also means in an emergency they can remove it (and if its not an emergency deal with the repercussions later).
If I am doing local then I use a kitchen safe, I pop the keys in, set the dial to how long I want it locked on for and it does the rest. If there's an emergency a quick hammer will break it open and allow me to get it off in a hurry (but will destroy the safe).
Numbered Security Plastic Padlock Seals Small Red 100 pcs per Bag https://www.amazon.com/dp/B088KQGXJF/ref=cm_sw_r_apan_glt_i_TGASY7RREQYK3BK30V5A