Holy Water - This is exactly what it says. Water that has been specially blessed and prepared by a priest for use by Christ's church. Holy water can be sprinkled with an aspergill, spray bottle, squirt bottle, or really large paint brush. It is important NOT to mix this with sewage, unwanted holy water should be disposed of directly into the ground.
Blessed Salt - Used either to lay around door jams and window sills, it can also be ingested. Blessed salt has a series of exorcisms placed on it.
Blessed items - These range from the crucifix or cross one might wear around their neck, to medallions, scapulars or prayer cloths. These items can be useful as a weapon in the fight against evil. They can also be misused as superstitions or even be the focus of inadvertent idolatry. Blessed items are a small part of the overall defense against evil, not a prominent part.
Oil - There are several types of Holy oil. The oil most likely needed for a cleansing would be the oil of the catechumens which is anointed at confirmation in liturgical churches. This oil is prepared by bishops in liturgical churches and is closely guarded by priests. It is unlikely you would be given any but a priest may well anoint you and your family with it while helping you fight evil.
Baptism - In and of itself baptism is a form of exorcism and is an excellent weapon in the war against evil.
Holy Communion (the Eucharist) - This sacrament is pivotal in combating evil and a regular participation in the Eucharist is a constant fortification against temptation and evil.
Prayer - Is the ultimate weapon against evil, it is your first and often last line of defense against the enemy. When you pray, do so out loud. This lets any evil that is in proximity hear that you are praying to the One True God and therefore align yourself with god the Father, the Son and the Holy Spirit. It also allows your guardian angels to be aware of your present situation. Remember that angels don't read minds either. Regular prayer is a key to strengthening your walk with God, and staving off the presence of evil. Suggestions for regular prayer include the daily hours of the liturgy, rosaries and chaplets.
Incense - preferably blessed by a priest, and something appropriate. Avoid most incense you would find at a "rock" shop. Try to obtain monastic or church blends. Resin or wood incense is good. Incense is a reminder that as the smoke rises so do our prayers which also provide a sweet smell to the Lord.
Candles - Are a good tool especially blessed beeswax candles, however it is important to avoid the "luck" candles you find at "rock" shops and the like. These candles have tall glasses and colorful pictures on them, often touting things like "money candle" or "Health candle". These candles are generally created for the purpose of sorcery. It is best to avoid them if at all possible.