Lol, you dumb fool.
Iron sand allows Sasori to be immune to all metallic weapons, as the magnetic force attracts all metallic materials. What's Hidan's Scythe made out of? Oh yeah... so you flop. Sasori can take away his only weapon, and kill him. Hidan also has no answer to his poison gas, which can subdue him, leaving him wide open for an attack. And if you hadn't noticed, almost, if not all of Sasori's 100 puppets contain a cutting material, whether it be a sword or anything else. The only reason Sakura was able to avoid (don't forget she got hit twice) his barrages is because of Chiyo's expertes in the art of puppetry.
Though since Iron sand repels his ONLY weapon, need I say more? And the way you claim Sasori is dumb is quite amusing. Sasori has a five in the databook, and is the most gifted Puppeteer in this manga. You're going to have to deal with it. I also hope you know he let himself get killed, he still had feelings.
Oh, and I just wanted to point out that Hidan has no means of breaking Hiruko. Hidan lacks the physical strength of Sakura, who was, as you know, trained by the biggest powerhouse in this manga, Tsunade. He simply can't stab it, as that would end inconclusively. It's too hard to be cut. Not to mention Hiruko has a poisonous tail, capable of reaching lengths way further than Hidan's scythe. So Sasori can just play with him from a distance.. It's the truth. While Hidan is immortal, he is still susceptible to pain, and one scratch would leave him in agonizing pain. While he may not die, it'd definitely hinder his performance throughout the fight.
Sasori stomps, negative difficulty.
I'm sorry, how do you know Hidan knows where Sasori's heart is? You can't prove it, so don't make assumptions. Hidan and Sasori are in different groups, so I see no reason for Sasori to reveal his true nature to Hidan, of all people. It's known that Sasori remained in his Hiruko puppet while in Akatsuki, so again, I don't see how Hidan could know.