When people talk about brute forcing on an adventure, they usually mean trying every inventory object on every puzzle.
Really though, there are four methods of brute force:
1. Map-checking
2. Item-checking
3. Puzzle-checking
4. Verb-checking
#1 for instance could be trying every feasible action in each room, checking them off as you go. #3 could be taking every item to a particular puzzle and testing each one out, hoping for a result. Occasionally a game will have an extra category particular for the game (for example, trying to use the magic words from Adventure in every possible room).
#4 is often overlooked but is quite handy for old adventures: trying everything that might plausibly be a verb for future reference. In particular I tested out SLIDE and got
>slide
Slide what?
Hmm. What slides? I tried the rubber mat from the beginning of the game:
>slide mat
under what?
Oho! I was in the first room, so I tried DOOR:
>slide mat under door
There’s not enough room under this door.
I could tell where this was going: there’s a puzzle that’s appeared in approximately 500 (*) other adventure games where a key has for some reason been left on the other side of a keyhole. To its credit, this appearance would be the first. A puzzle that could have been ornery later — it’s not obvious from the room description it would’ve been possible — turned out to be quite easy forewarned with this knowledge.
(*) Only a slight exaggeration.
Renga in Blue 
I remember doing a lot of #2 when I first started playing Infocom games … I’d type random nouns into the parser and note whether the parser was confused, or responded with “There was no verb in that sentence!”
It wasn’t often useful (knowing that there’s a “crown” somewhere in Leather Goddesses of Phobos is entirely worthless information), but it managed to be thrilling when I’d hit paydirt.
That’s funny. Figuring out that there is, say, a “crown” in Zork 2 isn’t useful, but it’s still fun. It also means that you know some of what you’ll be finding. For instance you can say that “In Zork 2, there’s a wizard, a crown, a coin, a robot, a club, a demon, and a brick” in the same game” without knowing about any of those items.
STUPID THIEF!!!
I was going to climb down the rope but he removed it. I’ve been everywhere and I haven’t found it. Now I have to restart when I had 421 points~ 421!!
What’s up with that, I ask you? What’s up with that?
Sorry for the rage, but I’m just so mad at the game right now.
I thought you said you had killed the thief already?
I have had the rope stolen, though. It was equally frustrating.
HHe must have snagged it some time before I killed him. I was taking more turns to explore and stuff, so it’s possible he could’ve stolen it at some point.
there’s a puzzle that’s appeared in approximately 500 (*) other adventure games where a key has for some reason been left on the other side of a keyhole.
My recollection is that the Zork II Invisiclues instruct the player to try the “well-known trick” of putting the mat under the door to catch the key. It certainly wasn’t well-known to me!
Oddly, my first encounter was from some mid-80s BASIC adventure game whose name I don’t remember (it was some spy game where you started from escaping ac cell using aforementioned trick). I suspect a lot of people first saw it in Zork II, though.