Liquidise is the process of chopping a solid material into a thick liquid, with or without the addition of, for example a quantity of water or milk, depending on the original moisture content of the solid in question. This is a process which is normally carried out using that specific kitchen appliance known as a blender, which is thus also known as a liquidiser.
This is of course a British English usage as it appears that in American English the term used is not 'liquidise' but rather 'liquify'. (And in any case would probably be liquidize with a 'zed', sorry 'zee'.) However within Britain, 'liquefy' or 'liquify' is generally used to refer to the process by which a solid is turned into a liquid by the application of heat, that is to melt. And the British regard melting something as very different from placing it a blender and pressing the 'on' switch.
Neither would the British use the term purée, which is regarded as a synonym for mash, which means to turn a solid into a paste, which of course is far thicker than a liquid, and thus a completly different thing altogether. (Or should be; this depends entirely on the competence of the cook in question.)
Therefore liquidising is what certain Peruvians do to frogs, or what Steve Parton, a thirty-nine year old male stripper from Norfolk, did to the corpse of his housemate Nelvaughn Brade after he'd killed him during an argument earlier this year. As it happens Steve Barton placed the former Mr Brade's remains in two oil drums which he dumped at a landfill site near King’s Lynn. And he would quite likely have got away with it as well, only he walked into Hunstanton Police Station and confessed all. He must have done a reasonably good job as it was reported that the police could only identify the body as a result of one single finger that had somehow escaped the blender. But the point is that the headline that The Sun newspaper instinctively chose for this story in its edition of the 25th May 2005 was 'Stripper liquidised his pal'.
Thus as far as the British are concerned if you chuck something into a blender and blitz it into submission, it doesn't matter whether it's a frog, you former best friend or a banana, you have liquidised it.
The Steve Parton story is reported at http://www.newcriminologist.co.uk/