Better to water heavily and infrequently to get better penetration and encourage the roots to go deeper rather than little and often which over time only encourages surface rooting and so exacerbates the problem.
Longer term do as much as possible to encourage deeper rooting to avoid the problem in future: aeration, relief of compaction, correct feeding, in other word good management.
Spike it first to get through the hard baked surface. And water it alot, and infrequently as said above.
H2pro is only really efective if it is in place before the drought, and water is applied early on, not when it is showing signs of distress. It needs to be applied to non drought soil, and needs repeat applications.
As always, this is a matter really that good lawn care could have prevented, rather than sorting it out when it has already happend.