It is not advisable to trade any stocks. You and the other traders will break-even as a group before transaction costs. But you will be massive loss makers due to transaction costs.
It's even worse for Irish shares because of the 1% stamp duty. Even if you buy CRH in London, you will pay 1% stamp duty.
If you don't mind losing your money by trading shares, then you should probably look at other forms of gambling such as spread betting. At least spread betting makes no pretences to be investment. If the extremely unlikely event that you make any money in the long term, your profits will be tax-free as it's gambling.