I don’t know the sound coming from the dark of a shell being racked in my Mossberg Maverick 88 is might effective.
No doubt, cycling a pump has a high pucker factor, if there is light, a scared female pointing a double, “clicking” the safety, should cause at least as high a factor. I have a Boito, o/u very short, in 12 gauge. Very effective.
1) You have eliminated your element of surprise.
2) You have given away your position.
3) Based on 1 and 2 above, you have increased risk to your safety.
Your shooter should be loaded, cocked, an locked.