Centralising Washer For Ceramic Bath?

[pototea]

Hi,

I have an enameled (ceramic?) bath in my Victorian house. The tap holes are bigger than the tap legs and it is causing some leakage. Here is a pic:

http://img209.imageshack.us/img209/5101/201209021229511.jpg

The silicone has been changed a number of times but there is still leakage and I keep getting water stains on my kitchen sealing!

My husband said there is something called a centralising washer like this:

http://www.toolstation.com/shop/Plumbing/Washers & F...

Does anyone know if:
1) this is the right kind of fixing for my tap
2) will it help?
3) what else other than silicone could fix the problem?

Thanks in advance