I've always been a proponent of attack explosives because you can choose who to attack, but now I'm having second thoughts. I just went over the $1mm/hr income mark and decided to start loading up on Sarin Gas explosives (30A for $325k), to be able to attack a wider range of opponents to make completing TL goals easier. So my profile attack is 56,347 and without explosives it's 44,629. I've bought about 200 Sarin Gas over the last few days which has added about 5k to my attack. However, I still lose explosives in attacks against people in the 34k-36k defense range. I also have 272 skill pts in attack thanks to the Black Widow. So here's my theory (apologies if it's already been stated before).
Explosives are used in the calculation (with all the other known/unknown fixed/random variables) as to whether you win the fight or not. However, whether you lose any explosives during the fight depends on your attack/defense minus the explosives. For example, if I had my 44k attack against a 36k defense, I may occasionally lose a fight here and there, but now with explosives, I don't lose the fight, I instead lose some explosives.
While I guess this makes sense to me, as I write it, this was not my understanding when I decided to spend $80,000,000+ on attack explosives. I was under the impression that a 56k attacking a 36k would win 10-0 no damage done end of story, and this doesn't seem to be case in my experience.
So, my new conclusion is that while adding attack explosives makes it more probably that you will win against a certain level of opponent, it substitutes the lose of the fight with lose of explosives instead. So, depending on how much you value a loss vs in-game money, it's not clear to me whether attack explosives are worth it or not any longer.