This is how we make frag plugs for those interested.
First get out your silicon mould of 121 frag plugs
Next mix up a mixture of cement. not to wet though as water will weaken the plugs when they are set in a silicon mould.
I like to hand work it so i know everything is mixxed
start working the mixture into the silicon mould (cleaning your hand is optional)
shake the mould a number of time to work the mixture to the bottom and work out any air bubbles.
And there you have it. just wait 24 hours and remove
Easy!