The phrase "etc once a week" suggests that there are numerous synonyms that can be used in place of "etc" on a weekly basis. Some alternatives to "etc" include "and so on," "and others," "and more," "among others," "including but not limited to," and "and the like." All of these phrases convey the idea that there are additional items to add to a list without needing to specify each one individually. Using synonyms like these can help improve writing by making sentences more concise and avoiding repetition. Varying word choice can also make writing more engaging and easy to read.