Those adaptors are for shavers/toothbrushes only and are used here in Ireland as those appliences are designed to connect to special ultra-safe bathroom shaver outlets. You can't fit a bigger fuse and don't attempt to bypass it.
Also DON'T connect a hairdrier to a 2-pin bathroom outlet marked shaver only it'll blow the fuse / cause a trip within a second and you'll have to explain it to the hotel!
You can pick up Schuko - Irish adaptors in nearly every department store (Roches Stores etc) in the centre of Dublin a lot of supermarkets Dunnes Stores, Tesco etc will stock them too. Dublin Airport will certainly have some in stock as will most electrical shops and even computer stores. They're quite a common accessory. shouldn't cost more than about ?2.99 MAX. They're fitted with a 13A fuse so you're protected on a ring circuit.
You can pick up rewirable plugs in any supermarket for around ?1.99 ish. They come with 13A fuses fitted as standard. One sollution is just bring a 4-socket power strip from home, cut the schuko plug off and pre-prepare the cable (leave the earth about 2cm, live about 1 cm and neutral about 1.5 cm) when you arrive all you'll need is a plug and a screw driver!
the plugs wire like this: http://www.esb.ie/main/energy_home/safety_plug.jsp