All you can do is try, like everything else when it comes to overclocking there isn't one setting for all.
There is very minimal risk when it comes to overclocking a monitor, it will either work or it won't.
A failed overclock will lead to failing to apply the refresh rate at all, black screen after applying/flashing black screen or distorted image/colours.
If any of them occur simply wait for the 15second count down to end and restore the original refresh rate or manually click no.
If 75hz doesn't work try a lower refresh rate, if it works you could try for a higher refresh rate.
You can also try the 'LCD Reduced' setting to try get a few more hz out of it.