I am the sort of a person who cares a lot more about flavour than the stats, so here's my nitpick:

The 'destructive brew' seems to be the core ability of the character, but one gains that from taking only one level of the class. I would opt for a list of successively more complex, powerful and varied explosives, which are learned much like magical spells, except obviously used and prepared as alchemical concoctions instead of magic. Also, to mention mechanics, I too have seen explosives' concussive force explained as crushing damage.

'Tapper' should only instantly tell if small spaces are empty or not - telling what's behind a door, if the answer is a large hall, should only mention a large hall - hearing about the existence of any denizens of large spaces from a simple tap makes no sense.

'Acidic mixture' has a poor name. It is a bonus to alchemy, not a new chemical brew. Perhaps 'Skill with acid' or 'Acid Mastery'.

Concussion Resistance... Well, sonic and force resistance certainly are rare, though I still say force is not concussive. I would split this up into two, possibly with a resistance of 5 at an earlier level, maybe pushing another ability to a later level to prevent making some extra juicy levels to grab of this prestige class.

Ooze ointment... I would prefer if this was another form of chemical. However, your explanation offered later - having come into contact with so many chemicals that the character simply is disgusting, is interesting. I propose the following: If a character has not bathed for N days (probably 3 or 4, maybe [n-demolisher level] while actively working on one's potions, one gains the advantage not as sweat, but as chemical residue on his skin and clothes. It cannot be bottled, but in addition to desiccating oozes, it will also lead to the suggested 'nauseating non-abominations who try to eat one'. However, it will also grant the character and possibly, if this ability has been 'on' for several days, the character's allies if one is close by, a noticeable penalty to most charisma-based checks.

X-ray vision is the thing I have the most problems with. A clearly magical ability for an otherwise mundane class, simply out of the blue? I would probably not allow this class in a game I am running based on this inconsistency alone, even though I feel that it actually fills a gap among class abilities, unlike many other player-made prestige classes.

Expert Demolition and Demolition Master seem too powerful to me, fluff-wise. The latter allows some bloke to break through an adamantium-reinforced stone wall made by greatly skilled dwarven craftsmen by knocking really well. It sounds like a shoddy attempt to make a 'memetic badass'. Also, there's a huge difference between comprehending the weak points of a wall and finding a way to overcome a demon's natural armour.

I propose toning those two abilities down a bit, but in exchange adding plenty of anti-construct abilities to the character's repertoire, since those would make perfect sense for a character built around the concept of destroying objects to go where he wants to.