Mate if you want to collect razors go on the lowest tide of the year, normally around 21st march. It is the only one time I go each year.
Even on the lowest tide of the year the level of the sea might not drop back far enough. The wind direction and state of the sea will contribute to the levels
If you wash out and catch nothing dont be put off it is a hit and miss thing. Out of the six years I have been doing the lowest tide. I have had two wash outs, three hunts that made it worth going and one amazing year. Coincidently the first year, which got me hooked. The tide retreated so far that dog fish were getting beached. Big cockles much bigger than your normal cockle were popping out the sand all around. We had enough to fill an onion sack on hughe cockles alone.
There is another very low tide mid September which I have gone a few times but I have not had much luck. The tide never retreated that well.
You have got to approach the holes without stamping too much as they dive, making them harder to retrieve.
People walking the shore line before you will make your life much harder. If you disturb them you will be able to see water push out of the hole sometimes shooting up a couple of inches.
I salt mine out. I walk about 10- 15 meters at a time salting holes then just pop back and get the ones, which have popped up.
Watch out for sneaky seagulls and dont take the dog as she will make all the razors dive.
Den