The use of SUBSTITUTE function is to substitute existing text with new text in a string. So you can use SUBSTITUTE formula to clean texts or sentences.
SYNTAX: =SUBSTITUTE(text_to_search, search_for, replace_with, [occurrence_number])
text_to_search - The text within which to search and replace.
search_for - The string to search for within text_to_search.
search_for will match parts of words as well as whole words; therefore a search for "vent" will also replace text within "eventual".
replace_with - The string that will replace search_for.
occurrence_number - [ OPTIONAL ] - The instance of search_for within text_to_search to replace with replace_with. By default, all occurrences of search_for are replaced; however, if occurrence_number is specified, only the indicated instance of search_for is replaced.