Clean method to remove nulls from sobject list

cleanList

Account firstAccount = new Account(Name='Test 5');
Account secondAccount = new Account(Name='Test 6');
Account thirdAccount = new Account(Name='Test 7');

List<Account> accountList = new List<Account>{null, firstAccount, null, secondAccount, null, null , thirdAccount, null };

List<Sobject> clean(List<SObject> inputSobjectList){
    Integer listSize = inputSobjectList.size();
    for(Integer index=0;index < listSize; ++index){
        if( inputSobjectList[index] == null ){
            inputSobjectList.remove(index);
            --listSize;
            --index;
        }
    }
    return inputSobjectList;
}

insert clean(accountList);