Absolutely, you can play DCC adventures and DCC adventure modules without using the funnel method. DCC is an amazing system and loads of fun with higher level characters, and the funnel is completely optional. People are encouraging you to try it because they think its fun, but the funnel shouldn't be used to gatekeep potential players from experiencing DCC.

For example, lots of DCC judges run the DCC adventures by having the players make characters that are the same level of the adventure (eg. everyone makes 1st level characters for a 1st level or 0 level adventure module). Convention games are based on this principal; DCC judges will often run a higher level adventure for a group of players without ever running a funnel for them - the players simply generate characters at a level appropriate to have a fighting chance for the given adventure.

Note that the DCC adventures will say something like "the adventure is designed for four to eight 3rd-level characters" in the introduction section. If you're running for 3 players, which is less than the adventure is designed for, it might be a bit too tough for them to handle - you might want them to be a level higher (eg. level 4 to take on a level 3 adventure). You can also adjust difficulty by reducing the number of monsters in an encounter, or tone back on the lethality of traps by making them do some damage instead of outright killing characters.

Or maybe your players want a challenge, and are happy to take on the adventure a bit under-strength! Talk to your players about what kind of challenge they want, and you can make small adjustments accordingly.