A portable mini-audio recorder works (I’ve used a Microtrack 24/96). It easily fits in a guitar case or gig bag. Trim the audio beforehand in an audio editor, and save clips as individual .wav files.
An advantage to using a computer / sampler with MIDI capabilities is that you can somewhat automate the process. Send a Start / Stop message to both the DAW sequencer and H9 / TimeFactor (or generate them within the application). Sample playback and looper recording begin & end together. Mute, and switch tracks to repeat the process with other samples.
There has to be similar options for tablets or iPads. A hardware drum machine can be used as a “System Real Time” generator.
