The chakra absorbing technique used by Hiruko is Dark Release: Inhaling Maw.
While in the case of Pain, or Preta path corpse to be precise, the technique is Blocking Technique Absorption Seal.
These two techniques seem to be no different right? No, it has a major difference.
Hiruko's Dark Release: Inhaling Maw
Classification: Kekkei Genkai, Ninjutsu, Chakra Absorption Techniques
Usage: Extract the physical and spiritual energy of another ninja, even from a considerable distance. He is able to completely remove the victim's chakra, potentially causing death.
Preta path corpse's Blocking Technique Absorption Seal
Classification: Kekkei Genkai, Ninjutsu, Dōjutsu, Fūinjutsu, Chakra Absorption Techniques
Usage: A highly advanced sealing technique that is capable of absorbing any chakra, regardless of any shape or nature transformation. As a result, this technique can absorb any ninjutsu based technique, rendering it ineffective on the user.
As I mentioned just now, there's a major difference, that is the classification. Note that Preta's path corpse's technique is classified as one of the Dōjutsu and Fūinjutsu.
Dōjutsu, which possesses a number of passive abilities that normal Ninjutsu don't. Moreover, Fūinjutsu is also part of the classification. Recall what is Fūinjutsu -- Fūinjutsu are a type of jutsu that seals objects, living beings, chakra, along with a wide variety of other things within another object. Ultimately, Hiruko's Ninjutsu absorption technique is just an absorption ninjutsu. With any Ninjutsu that possesses larger amount of chakra than his absorption technique, he will end up being killed. However, Preta path corpse's Ninjutsu Absorption Sealing technique is stronger than Hiruko's one. Do you remember that Jiraiya sealed Itachi's Dōjutsu, Amaterasu with his Fire Sealing Method(A kind of Fūinjutsu)? Even the highest level of fire release that cannot be extinguished with water or any other normal methods could be sealed, not to mention it's absorbed by Hiruko's absorption technique. That's the power of Fūinjutsu.
[Source and info are taken from Narutopedia. A wiki filled with SPOILERS about Naruto series :)]