exposure - If i use ISO 1600 to photograph stars will image stacking help reduce noise but also add more detail?

I would like to take better photos of the stars, especially the milky way, but my highest ISO setting is 1600. I have now learnt that image stacking can help reduce noise when taken with the same parameters but will it also provide more detail to the final merged image for editing? Ideally I would like to try it out, but we have had weeks of rain and no clear skies, so, hence me asking here first. Also, normally, I would take a 20 to 25 second exposure without stacking, what shorter exposure time would you recommend and also what number of images would be needed to get the best results when using stacking for this purpose?