You can guess WARMS, which will either give you the answer (to input on the next try) or eliminate 4 of the possibilities, leaving only 2 to guess.

That's a best case of 2 additional guesses and worst case of 3 (expectation of 2 1/3) which is better than your strategy, which has a best case of 1, worst case 6, expectation 3 1/2.