The podcast Coffee Break Italian (Seasons 1–4) is structurally very similar to Assimil: short 15–20 minute lessons with native speakers (Mark, Francesca, and Isla). The audio is 100% free. If you find a free PDF transcript online (or pay a small Patreon fee), you have a DIY Assimil.
Breve presentazione del metodo Assimil per imparare l’italiano: le lezioni giornaliere, i dialoghi naturali, l’approccio “subconscio”, e l’importanza dell’ascolto attivo. assimil italian audio free