He said it will also drill me to quickly tap, rack and fire.
Negative. Only tap, rack and fire when you KNOW the hammer landed on an empty chamber or snap cap. (Unless of course you have a dud or misfire in a REAL emergency.)
In the situation you describe the "click" may be because of a snap cap or it may have been a dud that just lodged a bullet in your barrel. Quickly loading one behind it and dropping the hammer could ruin a good handgun and may cause personal injury.
If you know it was a snap cap you've defeated the purpose of loading them randomly.