If the liquid is flammable or a mechanism for a bomb, it is not secure to force people to repack it in their checked-in luggage or dispose of it. This is because these types of items pose a significant security risk, and allowing them to be repacked or disposed of in the airport does not eliminate that risk.
Instead, security personnel should immediately flag and investigate any flammable or potentially explosive liquids and take appropriate measures to ensure the safety of passengers and airport staff. This might include confiscating the item, conducting additional searches or screenings, or contacting law enforcement.
By allowing these types of items to be repacked or disposed of, it can open a potential window of opportunity for an individual to cause harm to others. Therefore, security personnel should err on the side of caution and thoroughly inspect such items and make sure to handle it appropriately.