Does prayer efface all misdeeds and sins as long as one prays?

What you heard is correct. The five daily prayers expiate minor sins committed between them, as long as major sins are not committed, based on the Prophet's (peace be upon him) saying: "The five daily prayers, and Friday prayer to Friday prayer, and Ramadan (definition) to Ramadan, are expiations for what is between them, provided that major sins are avoided." Al-Nawawi holds that this expiation includes all minor sins, excluding major ones. Nevertheless, minor sins should not be taken lightly, as they can lead to major sins. The Prophet (peace be upon him) warned against belittling them, saying: "Beware of belittling sins, for the example of belittling sins is like a group of people who camped in the bottom of a valley. One came with a stick, and another with a stick, until they gathered enough to cook their bread. Indeed, belittling sins, whenever one is held accountable for them, will destroy him."