Hello ahmad090,
Had a play with this in a lab, it doesn't delete Objects, it appears to merely clear the Objects selected for viewing placement details in the lower pane - I do think though that it could be named more clearly than 'thrash', it is also curiously clickable when invisible (though that could just be nested-HOL issues).
Exercise an extreme quantity of caution and care when deleting inaccessible Objects via RVC/objtool - unless you are 100% positive that you are not deleting something you may still need (e.g. unregistered VM Objects) then please do just contact GSS for assistance.
There are several ways of determining the identity of inaccessible Objects if it is not clear from the GUI/RVC but the simplest method in modern versions is just checking via 'esxcli vsan debug object list' (writing it to a file and then either less and find or grep for the lines after 'inaccessible' showing the path and then another grep to trim out the excess (e.g. 'cat /tmp/debuglist.txt | grep -A30 inaccessible | grep Path' - note that obviously that will only find these for standard layout FTM=RAID1 3-component Objects as the output structure of a larger Object would be more than 30 lines between where it shows the health status and the Path).
Bob